1. Field of the Invention
This invention relates to a method of controlling a robot, in which a tracking motion by the robot is carried out to continuously position a torch distal end on a welding line during welding operation in case a welding torch is supported by the industrial robot, a welding object is rotated by an additional axis of a robot controller, and arc welding is made without moving the torch distal end in a direction along the welding line.
2. Description of the Related Art
There has been employed a robot tracking method in which a laser sensor is used to sense an area on the front side of a torch distal end of a robot, so as to repeatedly find the next target position on a welding line on a short cycle. The torch distal end is then sequentially moved toward the next welding target positions on the welding line.
However, in prior art method, the torch distal end is moved to the next target position along the welding line. Thus, the method can not be applied to welding in a mode where a cylindrical welding object is rotated while fixing the torch distal end (i.e., while preventing the torch distal end from moving in a direction along the welding line).